by Brian Truitt, USA TODAY

by Brian Truitt, USA TODAY

The Oscar-winning actor plays an aging knight who trains a youngster to help him keep evil at bay in Seventh Son, a fantasy adventure directed by Sergei Bodrov (Prisoner of the Mountains) and slated for release Oct. 18, 2013.

Wearing medieval costumes did wonders for Bridges, who in his six-decade career has explored everything from 19th-century Westerns to the high-tech world of TRON. "By the time you get through getting your clothes and makeup on and getting to the sets," he says, "you're pretty much there back in the Dark Ages."

Based on the young-adult novel The Spook's Apprentice by Joseph Delaney,Seventh Son casts Bridges as Master John Gregory, a "Spook" who imprisoned the evil witch Mother Malkin (Julianne Moore) centuries before.

Gregory's getting into the twilight of his years and the apprentices he keeps trying to recruit don't last very long, which becomes a serious problem for him when Malkin escapes and rounds up all of her followers for one momentous attack.

A Spook's apprentice can only be the seventh son of a seventh son, and after Gregory's last one is killed, he finds new backup in Tom Ward (Ben Barnes of the recent Chronicles of Narnia films) to help him fend off their supernatural enemies.

The cast also includes Alicia Vikander (Anna Karenina) as Alice, a relative of Malkin's, and Kit Harington (Game of Thrones) as one of Gregory's apprentices.

Bridges describes Gregory as gruff but also mysterious and feared. "He's an interesting cat. He's appreciated for keeping evil away, but he's also a frightening figure to the townspeople. When you mess around with darkness, some of that gets in you, too."

Of course, he's a pussycat compared to Moore's malevolent Malkin.

"In real life, she's gorgeous, and she's gorgeously grotesque" in the film, Bridges says with a laugh about his The Big Lebowski co-star. "She's really something to behold in this."

To get into the mythic mindset of Seventh Son, Bridges read some Joseph Campbell, and came in with a lifelong interest for the sci-fi and fantasy works of Tolkien, Bradbury and Heinlein.

Digging into that kind of material this year has been his day job -- in addition to filming Seventh Son, he's also starring in next year's R.I.P.D. with Ryan Reynolds, as undead police officers.